Fermented Ammoniated Condensed Whey as a Nitrogen Supplement for Lactating Cows

Seventy-five lactating Holstein cows were fed rations differing in the following additions of nitrogen to concentrate: none, 17% soybean meal, 2.5% urea, 9% and 18% fermented ammoniated condensed whey. The whey product contained 48% crude protein and was prepared by inoculating cheese whey with LactobaciUus bulgaricus, fermenting at 43 C for 24 h while infusing aqua ammonia (22% nitrogen) to maintain a pH of 5.5, and condensing to 54% solids. Treatments began about 130 days postpartum and lasted for 70 days. Corn silage was fed ad libitum and concentrate at .4 kg/kg milk. Dry-matter intakes of silage were lower for the negative control than supplemented rations. All nitrogen additions increased milk yields, particularly for high producing cows. Persistencies averaged .80, .89, .92, .86, and .89 for the respective treatments as compared to the pretreatment period. Milk yields increased linearly with increased whey. Liveweight gains were lower for negative controls than supplemented groups. Treatment did not affect content of milk fat, protein, or solids-not-fat, but production of these constituents was greater for supplemented groups. Rumen ammonia and urea nitrogen of plasma reflected nitrogen in rations. Fermented ammoniated condensed whey and urea equalled soybean meal in maintaining milk yields